(1) Field of the Invention
This invention relates to a novel sialic acid derivative, more specifically to a sialic acid derivative having an active carbonyl group in the molecule, a biological half-life elongating agent for a physioligically active substance using said novel sialic acid derivative, a binder of coupling gel for affinity chromatography and a sialic derivative composed of said novel sialic acid derivative combined with various amino compounds such as an amino acid and a protein.
(2) Related Art Statement
It has been known that a neuraminic derivative such as an N-acetylnueraminic acid, i.e., a sialic acid derivative has been present in the animal kingdom or on a cell surface of some bacteria as a sialo-complex (glycoprotein, glycolipid, oligosaccharide and polysaccharaide).
In recent years, the above sialic acid derivative is a compound regarded important in medical and pharmaceutical fields such as nervous function, cancer, inflammation, immunity virus infection, differentiation and hormone receptor, and has attracted attention as a pecular active molecule located on cell surface.
However, the actual function of the sialic acid derivative in the aforesaid sialic acid complex, still remains a matter of conjucture.
Also, the sialic acid derivative has been researched by many natural organic chemists and various derivatives having a simple structure have already been synthesized, but there has been not found a derivative which shows remarkable physiological activity.